The present invention relates generally to improvements in heating pads and particularly to portable heating pads having removable heat pads, removable gel packs and pressure bladders which provide warming capability.
The value of heat treatment for easing and preventing the onset of pain in muscle tissues is well established. For example, muscles which tend to cramp may be heated before strenuous exercise to enrich the blood supply to the appropriate areas. Means for effecting such heat treatment include the use of electrical heating pads and portable heating pads having reusable gel packs of the microwavable or chemical variety. Electrical heating pads are typically preferred over portable heating pads when heat treatment is needed over an extended period of time because electrical heating pads have a constant source of power and can achieve and maintain a maximum heat level. However, conventional electrical heating pads used in treating subjects in need of heat therapy suffer from the inconvenience of restricting the subject""s physical location because of the power cord attachment. Portable heating pads using gel packs suffer from temperature decay problems because they do not have a constant power source allowing them to maintain maximum heat levels. Thus, they lose their therapeutic heating effect rapidly due to heat transfer to the targeted body part and the atmosphere.
Typical devices for administering such heat therapy comprise the aforementioned heat sources contained within a suitably shaped fabric holder with a means for wrapping the respective heat source around a targeted body part. However, the efficacy of the resulting treatment depends in part on the intimacy of contact achievable between the heat source and the target anatomical region. The usual means of controlling the intimacy of contact is simply adjusting the tightness of the wrapping of the fabric holder around the targeted area. Because of the intrinsic difficulty of wrapping the fabric holder with sufficient precision, the comfort of the user is adversely affected if too tightly wrapped, or the efficiency of heat thermal transfer is respectively reduced if too loosely wrapped.
The typical methods of achieving optimal contact are largely based on the use of materials having elastic properties in the construction of the wraps. Examples of such materials include natural and synthetic rubbers and other synthetic elastomers. This approach is however inherently limited since the elastic property of the construction material is diminished by pre-stretching during the initial wrapping, and therefore, restricts further adjustment of the tightness between the wrap and the targeted body part.
Another method of adjusting the contact between the wrap and the targeted body part is a therapeutic pad having a pressure bladder. Therapeutic pads having pressure bladders have made use of external hand pumps and are disclosed in Re. 34,883. Such therapeutic pads, however, are bulky to carry and operate.
The present invention provides an improved portable heating pad that overcomes the above-described deficiencies of known devices. In an exemplary embodiment, the present invention provides a heating pad comprising an outer base member with strap attachments which can be adjusted in length to the size of the subject""s targeted body part, a removable heat pad which can be heated to a desired temperature prior to disconnecting the power cord, and a removable gel pack which can be heated to a desired temperature prior to attachment to the removable heat pad and thereby achieve more efficient extended thermal transfer. Having a removable heat pad with a connector allowing the power cord to be disconnected from the heating pad would allow the subject to be physically mobile after initial heat up of the heat pad. Such an enhanced design which affords heat therapy while allowing the subject physical mobility and a greater degree of control in the adjustment of the contact between the wrap and the targeted body part would enhance the comfort of the user as well as the efficiency of heat thermal transfer to the subject.
In a further embodiment, the present invention provides a portable heating pad comprising an outer base member having a layer of reflective material to reflect heat back to the removable heat pad and attached removable gel pack and the subject""s targeted body part and thereby achieve more efficient extended thermal transfer.
In a further embodiment, the present invention provides a portable heating pad having a pressure bladder which can be pressurized to enhance the surface contact between the removable gel pack attached to the removable heat pad and a targeted body part and which can be inflated or deflated so as to adjust the tightness of fit between the removable gel pack attached to the removable heat pad and the subject""s targeted body part. In an exemplary embodiment, the pressure bladder may be inflated using an internal manual pump which is integrated with the main body of the portable heating pad. Use of an internal manual pump which is integrated with the main body of the portable heating pad to inflate the pressure bladder so as to adjust the tightness of fit of the portable heating pad would be more compact and thus significantly more convenient to operate than pads using external pumps. Portable heating pads with pressure bladders utilizing such integrated hand pumps and with a disconnectable power source would therefore provide an enhanced mode of heat therapy to subjects in need of such therapy.
In a further embodiment, the present invention provides a portable heating pad comprising an outer base member with strap attachments which can be adjusted in length to the size of the subject""s targeted body part, a removable heat pad member, and a removable gel pack member which is vertically divided into a plurality of discrete segments. Dividing the gel pack member into a plurality of discrete segments would enhance the flexibility of the gel pack and prevent the gel from squeezing out from the points of contact with the subject""s targeted body part, thus preventing reduction of the mass of gel in contact with the targeted body part.
Accordingly, the present invention provides a portable heating pad for a subject in need of heat therapy comprising an outer base member wherein the outer base member comprises an outer layer of a heat reflective material and a resilient filler and an inner fabric cover and has strap attachments which can be adjusted in length to the size of the subject""s targeted body part, a removable heat pad member comprising a cover and an electrical heating element, wherein the cover comprises an inner layer having a plurality of fasteners and an outer layer, a removable gel pack member which comprises a heat-retentive gel which contacts an anatomical portion of the subject and which contacts the heat pad member and is releasably attached to the inner layer of that member by a plurality of complementary positioned fasteners. The electrical heating element is enclosed by the cover of the removable heat pad member and is substantially evenly distributed within the cover. To afford the subject physical mobility, the present invention conveniently permits preliminary heating of the gel pack member to a predetermined temperature prior to attachment to the removable heat pad member. The present invention also allows heating of the heat pad member to a predetermined temperature prior to or after attachment of the removable gel pack member prior to disconnection of the power cord from the portable heating pad.
The accompanying drawings, referred to herein and constituting a part hereof, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.